The percussion examination is an integral portion of every general physical exam of the thorax and many specialty exams including the pulmonary exam and the abdominal exam. The percussion exam is used to identify a variety of normal anatomical landmarks and to identify pathological conditions such as ascites, pulmonary infiltrates, and organomegally. The standard percussion exam is performed by placing one hand with spread fingers on the patient. One finger of the other hand is used to strike one finger of the hand on the patient in a brisk swinging motion. The resulting tapping action results in an audible sound which may be characterized as “tympanic”, “resonant”, “dull”, or a variety of other variations. These sounds are then used to identify the boundaries of organs or the presence of abnormalities.
The sound heard from the standard method of percussion is often very faint and therefore very difficult to interpret. In addition to being difficult to hear, the quality may be affected by the characteristics of the examiner's fingers themselves and the examiner's personal exam technique. The standard exam consists of multiple taps on the patient used for point to point comparison of the changes in sound at different places on the patient. Therefore, variations in the technique from one tap to another or one physician to another may affect the results of the exam.